Question

3. Which of these phrases show an equation?
A. 5n+5 B. 9y+4 C. 10+2 = 4x3
D. (5x8)=4​

Answer 1

Required Answer

Unexpectedly, there are two answers. C is a false equation, and D is a true equation.

Question

Which of these shows an equation?

• A. 5n+5
• B. 9y+4
• C. 10+2=4×3
• D. 5×8=4

Solution

What is an equation?

When the left-hand side and right-hand side are compared with an equal sign, it is called an equation, and it means both are equal.

C and D are both equations as they are compared with an equal sign.

P.S

Surprise your teacher by telling this answer!

Answer 2

Before moving onto the problem, it is necessary to know what does an equation exactly means.

Equation

An equation shows that two mathematical values or expressions are equal. In other words, in an equation:

$\rightarrow{\boxed{LHS = RHS}}$

[LHS = Left hand side of the equation]

[RHS = Right hand side of the equation]

Solution

According to the question, we should find which option is an equation. Let's check the options one by one.

Option - A, B

$\rightarrow 5n + 5 \: and \: 9y + 4$

In the above expressions, there are no equal symbol and atleast two mathematical expressions are needed to consider the above options as equation. Therefore, Option A and B are rejected.

Option - C

$\rightarrow 10 + 2 = 4 \times 3$

On adding in LHS and multiplying in RHS, we get:

$\rightarrow 12 = 12$

The above expression is considered as an equation since, LHS and RHS are equal.

Option - D

$\rightarrow 5 \times 8 = 4$

$\rightarrow 40 = 4$

But we know that 40 is not equal to 4. Since, LHS is not equal to RHS, this is not considered as an equation and this statement is said to be false.

Conclusion

Option - C, 10 + 2 = 4 × 3 is the expression, which is considered as an equation. Others are rejected.